The invention herein relates to the field of outdoor ambient temperature determination, and particularly to making such a determination in the context of heat pump systems.
As is well known, heat pump systems are operable over a wide range of outdoor ambient temperatures. Nonetheless, even though the heat pump systems which are in use today can in fact operate over the entire wide range, it cannot be expected nor is it true that their effectiveness of operation is constant over the entire operational range. In fact, over certain portions of the operational range the level of performance of the heat pump system varies considerably. The ambient temperature is therefore, typically directly measured and forwarded to controller memory for conventional use in a well known control arrangement to operate the heat pump system in a fashion which provides optimal performance. According to this fashion, ambient temperature is measured directly by a dedicated temperature sensor which detects the instantaneous temperature in the ambient region of sensor placement and provides a signal or indication representative thereof through a suitable electric line.
Such a typical heat pump system further employs and detects other parameters, beyond merely measuring the outdoor ambient temperature. One of these measured parameters is the refrigerant temperature at the outdoor coil. Simply stated, temperature is thus measured at two outdoor locations in current heat pump systems, at a cost of course of employing and maintaining redundant temperature detection mechanisms. As a result, the heat pump control system is able effectively to modify operational parameters of the heat pump system including blower and compressor speed, for example, according to current ambient temperature conditions.